This invention relates to a dual purpose thermal recovery system for reducing industrial air pollution and for advantageously utilizing normally wasted heat energy. In particular, the invention relates to a thermal recovery system which directly utilizes hot exhaust gasses from a cyclone incinerator for drying lumber in a kiln.
Increased public awareness of the need to protect the environment by drastically reducing industrial air pollution and by conserving the earth's natural resources as well as specific legislation such as the Air Pollution Control Agency regulations have made it incumbent upon industry to develop new methods and means for operating within reasonable environmental guidelines.
In industrial operations wherein waste product production is voluminous, the problem is particularly vexatious. Due to the impracticability of ocean dumping and in view of the many difficulties connected with the sanitary land fill operations, incineration of waste materials has traditionally been industry's solution to the disposal problem. However, many present day incinerating operations do not meet environmental standards inasmuch as they often involve direct exhaustion of high temperature pollutant laden products of combustion into the atmosphere. Such systems are also generally wasteful of the energy contained in such combustion products.
Many prior attempts have been made to address these and other related problems. Examples of such attempts are found in U.S. Pat. Nos. 1,809,628; 2,171,535; 2,553,452 2,933,826; 2,938,714; 3,233,664; 3,486,841 to Johnson, Berg et al, Guthrie, Justuce, Gerrish, Jacobs, and Betz, respectively.
While many of the prior systems attempted to recover waste heat and to utilize such energy for beneficial purposes, none have provided a simple and practical means for directly using hot waste gasses for a particular purpose by means of controlling the temperature and volume of such gasses sent to the point of utilization through the controlled mixture of such gasses with cool ambient air and by the constant volume pumping of the mixed gasses to the point of utilization. Such a system which appears to have eluded industry thus far, represents an economically viable add-on or accessory means for attachment to existing incinerator structures without prohibitively expensive plant modifications or scrapping of existing apparatus.